Surgical resection of the primary tumor improves survival in patients with locoregional stage T1 nasopharyngeal carcinoma: a propensity score-based matched analysis

Abstract

Background Surgery at the primary site of nasopharyngeal carcinoma (NPC) remains controversial. This study aimed to investigate the efficacy of surgery in patients with stage T1N0-3M0 NPC.Methods We reviewed 1803 patients with newly diagnosed stage T1N0-3M0 NPC from the Surveillance, Epidemiology, and End Results (SEER) database for the period 2004–2015. The Kaplan-Meier method and propensity score matching (PSM) analyses were used to compare cancer-specific survival (CSS) and overall survival (OS) between surgery groups and no-surgery groups. Restricted cubic spline regression (RCS) was used to assess the relationship between age and the hazard ratio of mortality. Independent risk factors associated with OS and CSS were identified by Cox ratio hazard regression analysis employing a backward stepwise method, which was used to develop prognostic nomograms for locoregional T1 NPC patients. The correlation index and calibration curves were used to assess the performance of the model. An online dynamic nomogram for CSS was also developed to assist the clinic in better using the predictive model.Results The study examined 1803 patients, of whom 242 received surgery, and the remaining 1561 did not receive surgery. Before PSM, Kaplan-Meier analysis showed that OS and CSS were significantly longer in the surgery group than in the non-surgery group (P < 0.001). After 1:1 matching, similar results as above could be observed, that is, patients in the surgical group had significantly better OS (P < 0.001) and CSS (P = 0.0018) benefits. Subgroup analysis further showed that almost all subgroups undergoing surgery had superior OS and CSS, except for patients with tumor size > 30 mm and primary site located in the anterior wall of the nasopharynx. Finally, COX regression analyses showed that age, sex, marital status, histological type, N stage, tumor size, radiotherapy, and surgery were independent prognostic factors for OS and CSS.Conclusions This study indicated that surgery significantly improved the OS and CSS of patients with stage T1N0-3M0 NPC. The nomograms we established have satisfactory performance and may provide a reference for the clinic. Further prospective large studies are still needed to validate the results.